Sept. 30, 2009 -- Streptococcal infections, which include strep throat and strep pneumonia, don't appear to make Tourette's syndrome, tics, or
obsessive-compulsive disorder more common, a new study shows.

That study, published in the advance online edition of Neurology, is
based on data from 4,774 children and young adults in the U.K.

The group included 129 patients with obsessive-compulsive disorder (OCD),
108 patients with Tourette's syndrome, and 18 with tics.

The researchers -- who included Anette Schrag, MD, of the Institute of
Neurology at University College London -- checked all participants' medical
records, looking for any pattern of strep infection within two to five years of
diagnosis of OCD, Tourette's syndrome, or tics.

Schrag's team went looking for those patterns based on earlier studies that
suggested that strep infection could cause neuropsychiatric disorders. But
Schrag and colleagues found no evidence of that connection.

Schrag and colleagues note that their findings don't rule out any
possibility of such a link, but that a very large, prospective study that "may
be prohibitively expensive" isn't supported by current evidence.